diff --git a/problems/0203.移除链表元素.md b/problems/0203.移除链表元素.md
index 6fd9b66f..5622fd1c 100644
--- a/problems/0203.移除链表元素.md
+++ b/problems/0203.移除链表元素.md
@@ -385,7 +385,8 @@ function removeElements(head: ListNode | null, val: number): ListNode | null {
         if (cur.val === val) {
             pre.next = cur.next;
         } else {
-            pre = pre.next;
+            //此处不加类型断言时：编译器会认为pre类型为ListNode, pre.next类型为ListNode | null
+            pre = pre.next as ListNode;
         }
         cur = cur.next;
     }